His legal career began long before he was named FBI director under President Obama in 2013. As a federal prosecutor in New York, he brought charges against lifestyle entrepreneur Martha Stewart. He also worked as a General Counsel for the defense contractor Lockheed Martin, and as a lawyer for the hedge fund Bridgewater.

But Comey is indisputably best known for his role in the 2016 presidential campaign. His profile skyrocketed after he held a news conference about his agency's investigation into Hillary Clinton's emails. He later sent a letter to Congress days before November's election about additional emails uncovered in that investigation.

His term as FBI director was supposed to last a decade. But Trump fired Comey in May after fewer than four years. Trump removed the man who was responsible for the bureau's investigation into whether members of Trump's campaign colluded with Russia to interfere in the U.S. election.

"Throughout his career, James Comey has had to face one difficult decision after another as he has served the leaders of our country," said Bob Miller, the president and publisher of Flatiron. He said Comey's book will give "unprecedented entry into the corridors of power, and a remarkable lesson in leadership itself."